CN1775700A - Method for dry-treating municipal sludge by biological dehydrating machinery - Google Patents

Abstract

The invention relates to a method for processing the mud in the city waste water processing factory, including the following steps of: a. mixing the dehydrated mud in the waste water processing factory (moisture content 78%) with mechanically dried mud particles with moisture content of 10% below to make the moisture content down to 50%-55%; b. adding biodehydrating bacterial strains into the biodehyrating tank; c. biochemical raising temperature and reacting for 8-10 days to make the moisture content down to below 35%; d. feeding the biodehydrated city mud with moisture content of below 35% into a mechanical drying system for drying to make the moisture content down to below 10%, returning a part of finished mud particles to mix with wet mud; e. the rest is the final product of the city mud processing and able to be used as fuel and soil modifying agent or is buried finally. The invention largely reduces operating expenses and applies to large scale mud processing and can make multichannel processing according to mud quality.

Description

The method of dry-treating municipal sludge by biological dehydrating machinery

Technical field

The present invention relates to the treatment process of a kind of municipal wastewater treatment plant mud.

Background technology

Adopt the sewage work of second-stage treatment technology in operational process, can produce a large amount of mud.Contain hazardous and noxious substances such as large amount of organic, pathogenic bacteria, heavy metal in the mud.Generally in Sewage Plant, all be provided with the treatment facility of sludge digestion and thickening at present.Can reduce to about 80% through moisture percentage in sewage sludge after these processing, still contain a large amount of pollutents.Put as improper conducting oneself well, certainly will bring severe contamination to environment.At present have following several to the disposal technology of the dewatered sludge of Sewage Plant in the world: compost, mummification, burning, landfill, fusion etc.Landfill is owing to can cause that serious secondary pollution is banned use of by developed country gradually.Fusion is the technology that realizes sewage sludge harmlessness to greatest extent, but its disposal costs is very expensive, in land resources country very in short supply, and as Japan, development very fast.Composting production be owing to will be applied to the farmland, aspect Environmental Health and risk restriction tighter, and need a large amount of auxiliary materials.Mummification and burning are a kind of reasonable disposal options, and product resourceization utilizes degree very high, and it is very fast that present this method develops abroad.

The present most of sludge of sewage treatment plants of China all adopts the disposal options of outward transport landfill, has caused very serious pollution to environment.Sludge disposal has become current focal issue.The technology and the equipment comparative maturity of the direct mummification of developed country's municipal sludge at present, the approach of its product resource utilization is also wider, what but mummification was adopted is that heat transmits transpiring moisture, and the municipal sludge water ratio is about 80%, therefore be below 10% with sludge drying to available water ratio, then its required working cost is very expensive, and the working cost of mummification wet mud per ton is about 200 yuans, and this is to hinder the basic reason that this technology is extensively promoted in China.Municipal sludge dispose utilize aspect, some reports are also arranged, and be " 00132414.4 " just like application number, name is called: " utilizing municipal sludge to produce the method for biological organic composite fertilizer ", application number is: " 03129102.3 ", name is called: the patent application of " a kind of sludge fermentation dry fertilize preparation craft " etc.But these technology are all having the some shortcomings part aspect the municipal sludge disposal practical application.As application number be: in the patent application of " 00132414.4 ", fermentation time is about 4 weeks, cycle is oversize be unfavorable for that large-scale sludge disposal, final mummification mode use at 60 degrees centigrade of drying modes, long and temperature of baking needed time is low to be not suitable for sterilization; Application number is in the patent application of " 03129102.3 ", and the product water ratio is 10%～20%, the higher resource utilization that is unfavorable for, and the mummification temperature is 80 degrees centigrade, is unfavorable for sterilization.In addition, more than two kinds of technology common deficiencies be exactly all to be a kind of mode of making fertilizer, (this situation is very general) just can not use under municipal sludge heavy metal content situation not up to standard, simultaneously these two kinds of technology all are not suitable for large-scale sludge disposal.

Summary of the invention

The objective of the invention is to reduce effectively moisture percentage in sewage sludge, to reduce the working cost of mud machinery mummification.The technical scheme that is adopted is for achieving the above object:

The method of dry-treating municipal sludge by biological dehydrating machinery of the present invention may further comprise the steps:

A. Sewage Plant dewatered sludge (water ratio 78%) be that granule sludge below 10% is mixed to water ratio 50%～55% through mechanical mummification water ratio;

B. in the biologically dehydrating pond, add the biologically dehydrating bacterial classification;

C. through biochemical temperature reaction in 8～10 days, water ratio was reduced to below 35%;

D. the biologically dehydrating municipal sludge of water ratio below 35% enters mechanical anhydration system to carry out mummification to water ratio is below 10%, and a finished particle part is returned with the mud that wets and mixed;

E. rest part is that municipal sludge is disposed final product, can be used as fuel, soil improvement agent etc., or final landfill disposal.

Sludge organism dewatering machine anhydration system combines biologically dehydrating with drying process, with water ratio below 10% dried particle and wet mud to be mixed into water ratio be 50%～55%, satisfy the operational condition of biologically dehydrating, then the biologically dehydrating bacterial classification is mixed with wet mud, make full use of the exothermic effect of aerobic microbiological in biochemical reaction, utilize biological respinse heat, within a short period of time, (8～10 days) were with the moisture evaporation in the municipal sludge, water ratio is reduced to about 35%, utilize mechanical drying equipment that mud is further disposed the water ratio that makes it to reach below 10% then, machinery mummification granule sludge water ratio can reduce to 8%, form hard homogeneous granules, resource utilization degree height satisfies municipal sludge ultimate disposal requirement.

The invention has the beneficial effects as follows that this method utilizes biological drying earlier to reduce moisture percentage in sewage sludge significantly, enter mechanical mummification again, therefore reduced the working cost of mechanical mummification significantly.This system is applicable to large-scale sludge disposal, and the wet mud of day processing can reach the hundreds of ton.Mechanical mummification temperature is stopping 15min more than 100 degrees centigrade simultaneously, can fully realize the product sanitisation, and drying particles is finished synchronously, its product is for evenly spherical, diameter is between 1～4mm, utilize approach various, can be used for fuel, fertilizer, soil conditioner or the like, can be according to mud shale disposing by all kinds of means; The mechanization degree height also is fit to large-scale production very much simultaneously, has tangible practical significance for the handling problems that solves China's municipal sludge.

Description of drawings

Fig. 1 is the process flow sheet of the inventive method

Embodiment

Embodiment 1:

Be that the dewatered sludge particle of 78% dewatered sludge and water ratio 8% mixes by 1: 0.67 mass ratio and makes water ratio reduce to 50% with water ratio.Add the biologically dehydrating bacterial classification simultaneously.Mixture is stacked in the forced ventilation bar-shaped trough, and windrow thickness is 1.2～1.5m, and width is 3～6m, and length can be adjusted according to the material total amount.Establish automatic stack turner on the groove.The control ventilation is 0.1m ³/ (minm ³), the turning frequency is first three days every day 1 time, back turning in 5～6 days once can be monitored according to temperature therebetween.Dehydration initial stage temperature rises very fast, just need carry out turning in temperature during greater than 65 degrees centigrade.Can drop to below 35% according to 8 days～10 days windrow water ratio of weather condition.Be delivered to belt machinery mummification equipment by travelling belt then, by the warm air evaporation sludge water content granulation simultaneously of gas-firing, the finished product water ratio is 8%, and particle diameter is adjustable at 1～4mm.Product can be done fuel, overburden soil, soil conditioner etc. according to the mud shale.

Claims (2)

1. the method for a dry-treating municipal sludge by biological dehydrating machinery may further comprise the steps:

A. Sewage Plant dewatered sludge (water ratio 78%) be that granule sludge below 10% is mixed to water ratio 50%～55% through mechanical mummification water ratio;

B. in the biologically dehydrating pond, add the biologically dehydrating bacterial classification;

C. through biochemical temperature reaction in 8～10 days, water ratio was reduced to below 35%;

D. the biologically dehydrating municipal sludge of water ratio below 35% enters mechanical anhydration system to carry out mummification to water ratio is below 10%, and a finished particle part is returned with the mud that wets and mixed;

E. rest part is that municipal sludge is disposed final product, can be used as fuel, soil improvement agent etc., or final landfill disposal.

2. the method for dry-treating municipal sludge by biological dehydrating machinery as claimed in claim 1 is characterized in that, mechanical mummification granule sludge water ratio can reduce to 8%.

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